Improvement in devices for enlarging wells



atrasada amitiee.

THOMAS DONNELLY, or PiTT'sB-Une, PENNSYLVANIA.'

Letters Patent N, 111,620, dated February 7,1871.

' IMPRovsMsNT 'I N nei/less FOR- ENLARGING WELLS.

'The Schedule referred to in these Letters Patent andmaking part of the sanie.

' To' all whom lit may concern.-

Beit known that I,`THoMAs DONNELLY, of Pittsburg, in the county of Allegheny and State of Pennsylrania, have invented a new and Improved Well- K Mouse or Device for Enlarging Wells; andI do hereby declare the following to be a full, clear, and'exact description of the saine, reference being had to the accompanying drawing making a-part `of this specifi.- cation, in which- Figure lis aside elevation, with one of the cutting- .bars removed; and

' Figure2 is a detached longitudinal section of the adjustable-knob onpthe drill-rod.

This invention relates to an arrangernentot' four or there' cutting-bars, which are jointed at their upper ends, in sockets formed at the basenof a stock, said cutting-bars being held vertical-with their backs against the stock, by means of springs attached to a rin'g that is slipped over and vsuitably secured to the stockkthere being a jar-stem connected with. said stockin such manner as that the latter has a vertical play thereon,` on which jar-stern a knob is s o secured that it may be slipped upward or downward on the stem, said knob being provided with as many external' grooves running lengthwise as there are cuttingbars, so that when the stock and cutting-,bars are forced downward the latter at the same time are, by reasonrf their riding the springs in the grooves of the knob, forced outward until they strike the-walls of the well and thus enlarge the bore.

In the drawinga is the stock. b, the sockets,lconstruct ed at the base of the same. c, the cutting-bars, jointed at their upper ends in the sockets b.

d, a ring, that is slipped over the stock a, and has attached to it at points equidistaut apart springs, o, which hold the cutting-bars against the stock.

e is the jar-stein, which enters a cylindrical orifice.

bored in the lower part of the stock a, and is provided with a head that slides in a slot cutin the stock above 'the parts of a jar.

inthe -knob 71., and'corresponding in number with the cutting-bars. V

Secured at oneend in these groovesfil are springs, n, which serve to relieve the cutting-bars i'rom too great a shock.

The drill having been removed from the rod and the above-described apparatus attached in its place, the latter is let down into thewell until the jar-stem strikes the bottom.; the cutting-bars are then forced downward, and, coming in contact withA the springs and rounded bottom of the grooves, they are Aforced outward and in contact with the wall of the well as they descend with Asuiicient force to chip awayrthe' surface.

I The extent to which the cutting-bars are forced o ,utwardmay be regulated by changing the position of' the knob on the-stem.

-' The springs prevent the cutting-bars frorn'strik-- ing with too great force against the .walls of the well. As soon as the apparatus is drawn upward above the knob the spring attached tothe ring .on the stock forces them against the stock,'sc as-to be out of the way in withdrawing them from the well.

Having thusdescribed my invention,

That I claim as new, anddesire to secure by Letters Patent, is- I The combination of the lstock a, sockets b, cuttingbars c,.springs d, jar-stem c, and knob h, as and i`or THOS. DON N ELLY.

. thepurpose described.

i Witnesses:

GEO. W. HUMBERT, ANDREW HUMBERT. 

